It is generally desirable in the packing industry, to provide types of packings, packing processes and related equipment, which make it possible to pack different types of food products, so as to preserve for as long as possible the original structure of the machinery, and the operating characteristics thereof.
The processing of liquid or semi-liquid food products for the purpose of conferring to them characteristics of long-life at room temperature within suitable containers, presupposes a sterilization carried out, e.g., by means of a so-called "UHT" (ultra-high temperature) plant. This includes a step of heating to 135.degree.-150.degree. C., a dwell step at this temperature and a step of cooling to about 20.degree. C. with the subsequent delivery into the main distribution line to the aseptic packing machines. For the sterilization then of the machines and plants for packing long-lasting products, an operation cycle starts with the chemical washing of the components which will come into contact with the product.
In particular, the product delivery regulation and level control device must be washed, and it is usually at the end of the delivery pipe and placed inside the tube of packing material which is being formed. For such an operation to be made possible, the device is usually dismantled, with consequent time and production losses.
Moreover, regulation devices positioned inside the product within the tube of packing material being formed do not seem particularly suitable and universal with the varying of the density of the product to be packed, especially if they operate on the basis of hydrostatic or hydrodynamic principles. It is thus necessary to replace and fit them to the liquid or semi-liquid products, and to the presence of solid particles.